1. Field of the Invention
The disclosure relates generally to disc navigation and, more particularly to DVD navigation systems and methods by a check function for using IFO (DVD information) files or BUP (backup) files.
2. Description of the Related Art
Digital Versatile Discs (DVDs) are high capacity CD-size disc for video, multimedia, game and audio applications. Due to high quality requirements of video and audio, DVD has gradually become the most popular format for playback of prerecorded video.
In DVD specification, IFO, BUP and VOB (Video Object) files are utilized. IFO files include a plurality of tables for recording related navigation information such as chapters, subtitle tracks and audio tracks. BUP files are backup files of the IFO files. VOB files contain video, audio, subtitle, and menu content. FIG. 1 is a schematic diagram of DVD-Video navigation. In front-end 110, a file system 112 reads and stores data from a disc 116, such as DVD, via a loader 114. The data includes the IFO, BUP and VOB files. Tables in these files include Video Manager (VMG), Video Title Set (VTS), VMENU (Video Menu), VPGC (Video Program Chain), VPG (Video Program), VCELL (Video Cell), and VOBU tables. These tables are layered. For example, VTS is on VMG, VPGC is on VTS, VPG is on VPGG, and the like.
Several modules including VMG module 122, VTS module 123, VMENU module 124, VPGC module 125, VPG module 126, VCELL module 127, and VOBU module 128 are required for DVD-Video navigation. The modules can handle their respective tables. The VMG module 122 reads the corresponding table from the file system 112 via a utility 121, and decodes the corresponding table to obtain and output related information to the VTS module 123 or the VMENU module 124. VMG is the table for all contents for all VTSs. VMG is composed of control data referred to as VMGI, VOS of VMG menu, and backup of the control data. The control data is static information for playing back titles and providing information to support user operations. VOS is a collection of VOBs used for menus that support the volume access.
The VMENU module 124 receives information from the VMG module 122, reads corresponding tables from the file system 112 via the utility 121 accordingly, and decodes the corresponding tables to obtain and output related information to the VTS module 123. VMENU module 124 is defined as the display image which includes selection items (Buttons).
The VTS module 123 receives information from the VMG module 122 and VMENU module 124, and reads corresponding tables from the file system 112 via the utility 121 accordingly, and decodes the corresponding tables to obtain and output related information to the VPGC module 125. VTS is a collection of titles. Each VTS is composed of control data referred to as Video Title Set Information (VTSI), VOS for the VTS menu, VOS for titles in a VTS, and backup control data.
The VPGC module 125 receives information from the VTS module 123, and reads corresponding tables from the file system 112 via the utility 121 accordingly, and decodes the corresponding tables to obtain and output related information to the VPG module 126. VPGC is composed of playback information referred to as Program Chain Information (PGCI) and the cells in VOBs needed for the playback of Program Chain (PGC).
The VPG module 126 receives information from the VPGC module 125, and reads corresponding tables from the file system 112 via the utility 121 accordingly, and decodes the corresponding tables to obtain and output related information to the VCELL module 127. VPG is a group of cells defined in a PGCI. Programs are used to divide a PGC into pieces. Different modes are defined. If the PGC is in Random/Shuffle mode, one of the programs is selected randomly. If the number of programs in a PGC is zero, the PGC is a dummy PGC.
The VCELL module 127 receives information from the VPG module 126, and reads corresponding tables from the file system 112 via the utility 121 accordingly, and decodes the corresponding tables to obtain and output related information to the VOBU module 128. A VCELL is a unit formed by compiling appropriate sections in a VOB and provides a structure for directing presentation of a part of or the whole VOB.
The VOBU module 128 receives information from the VCELL module 127, finds the address and length of VOBUs needed for playback, and directs the back-end 130 to play back. VOBU is a part of a cell with the presentation time period. VOBU includes video data, audio data, sub-picture data, PCI data and the Data Search Information (DSI) data.
FIG. 2 is a schematic diagram of DVD-Audio navigation. In addition to the modules of DVD-Video navigation, ATS module 141, APGC module 142, ASV module 143, and APG module 144 in DVD-Audio navigation are further required. In DVD-Audio navigation, AMG module 140 may be instead of VMG module 122 of DVD-Video navigation.
The AMG module 140 reads the corresponding tables from the file system 112 via the utility 121, and decodes the corresponding tables to obtain and output related information to the VTS module 123, the VMENU 124, and the ATS module 141. AMG is the table for all contents in DVD-Audio zone and DVD-Video zone (if present) for audio player. AMG is composed of Audio Manager Information (AMGI), VOS for AMG menu, and a backup of AMGI.
The ATS module 141 receives information from the AMG module 140 and the VMENU module 124, reads corresponding tables from the file system 112 via the utility 121 accordingly, and decodes the corresponding tables to obtain and output related information to the APGC module 142. ATS is a logical unit defined by the Audio Only Titles (AOTT) for audio player. Two types of ATSs are provided. One is composed of Audio Title Set Information (ATSI), Audio Object Set for AOTT, and a backup of ATSI. Another is composed of ATSI and a backup of ATSI. In this case, an Audio stream in VOBs, recorded for Audio with Video Title (AVTT) is referred as the object of AOTT.
The APGC module 142 receives information from the ATS module 141, reads corresponding tables from the file system 112 via the utility 121 accordingly, and decodes the corresponding tables to obtain and output related information to the ASV module 143 and APG module 144. APGC is a logical unit for presenting a part of or the entire of contents. It is composed of PGCI on which the order and the essence of the presentation are described, and zero or more cells to be presented.
The ASV module 143 receives information from the APGC module 142, reads corresponding tables from the file system 112 via the utility 121 accordingly, and decodes the corresponding tables to obtain related information. ASV is the logical unit defining the collection of ASV to be presented together with audio data by video capable audio player. ASV is composed of Audio Still Video Set Information (ASVSI), Audio Still Video Object Set (ASVOBS) and a backup of ASVSI.
Similarly, the APG module 144 receives information from the APGC module 142, reads corresponding tables from the file system 112 via the utility 121 accordingly, and decodes the corresponding tables to obtain related information. APG is a logical unit for dividing the contents in an APGC. APGC may be divided into integer number of APGs. The APG shall be composed of integer number of cells.
The information generated by the VOBU module 128, ASV module 143, and APG module 144 can be used to request the back-end 130 to play back.
As described, the BUP files are backup files of the IFO files. The backup files can be used to replace the IFO files if the IFO files are lost or damaged. However, no solution for DVD navigation with using BUP files when IFO files are lost or damaged is currently used.